1. Field of the Invention
The present invention relates to an apparatus for controlling the closing motion of a vehicular sliding door from an open position to a closed position with an actuator.
2. Description of the Related Art
Some motor vehicles incorporate a so-called power sliding door which can be opened and closed by an actuator such as an electric motor. The power sliding door includes a motor unit for opening and closing a door panel, the motor unit being mounted on a vehicle body and operatively coupled to the door panel by an endlessly looped cable.
If the motor unit is supplied with electric energy at all times, then it makes the power sliding door relatively costly because of its energy consumption even when the door panel remains closed. To avoid the above drawback, the power sliding door is generally of such a type that only when the door panel is closed, electric energy is supplied to the motor unit in response to a signal from the door panel. Therefore, an external switch is required to energize the motor unit when the door panel is to move from the open position to the closed position.
In order to eliminate an external switch and allow the door panel to start being power-operated with a manual initiating action from outside of the motor vehicle, there has been developed a vehicular door controller as disclosed in Japanese laid-open patent publication No. 6-344773, for example. The disclosed vehicular door controller has an electric power unit for selectively moving the door panel in an opening direction to an open position or in a closing direction to a closed position, a detector for detecting a door motion in either the opening direction or the closing direction, and an operating unit for energizing the electric power unit to move the door in either the opening direction or the closing direction depending on the detected door motion.
While the detector can detect a door motion in either the opening direction or the closing direction, it is unable to identify whether the door motion is manually triggered or caused by an accidental force such as a shock. Usually, therefore, the operating unit starts energizing the electric power unit after the door panel has continuously moved a certain distance. As a result, a person who wants to open or close the door panel needs to move the door panel, which is relatively heavy, for a relatively long distance until the electric power unit starts being turned on. The person is thus subject to an excessive load in opening or closing the door panel.